JP3496160B2 - Method for producing aluminum alloy foil for electrolytic capacitor electrode - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aluminum alloy foil which can obtain an electrode foil for an electrolytic capacitor having a high capacitance and a small leakage current.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture an electrode foil for an electrolytic capacitor (particularly, an anode foil), an aluminum alloy foil is subjected to an etching treatment and a large number of fine holes are formed on the foil surface to reduce the surface area of the foil surface. Expansion is taking place.
This increase in surface area is to increase the electrostatic capacitance of the electrode foil for electrolytic capacitors. Therefore, in order to obtain an electrode foil for an electrolytic capacitor having a high capacitance, it is necessary to use an aluminum alloy foil having good etching characteristics.

Various studies have already been conducted on what kind of aluminum alloy foil has good etching characteristics, and the following tentative conclusions have been obtained. That is, regarding the internal structure of the aluminum alloy foil,
It is said that the more crystal grains having the cubic orientation (the higher the cubic orientation ratio), the better the etching characteristics. This is because the etching progresses along the crystal grains having a cubic orientation, so that tunnel-shaped etching pits perpendicular to the foil surface are generated at a high density, which greatly contributes to the expansion of the surface area.

Various proposals have also been made for a method of obtaining an aluminum alloy foil having a high cubic orientation ratio. For example, Japanese Examined Patent Publication No. 54-11242 discloses that after cold rolling, intermediate annealing is performed at 180 to 350 ° C., then finish cold rolling is performed at a working rate of 5 to 35%, and then final annealing is performed to obtain a cubic orientation ratio. A method of obtaining a high aluminum alloy foil for electrolytic capacitor electrodes is disclosed. Further, JP-A-57-97614 discloses
After precipitating solute atoms in aluminum, the reduction rate is 60%
Cold rolling is performed as described above, then intermediate annealing is performed at 200 to 380 ° C, then finish cold rolling is performed at a working rate of 5 to 70%, and then final annealing is performed, and an aluminum alloy for electrolytic capacitor electrodes having a high cubic orientation ratio is used. A method of obtaining a foil is disclosed.

In Japanese Patent Laid-Open No. 4-314439 and Japanese Patent Laid-Open No. 4-231441, the homogenization treatment is performed in two steps, that is, 56
After the primary heat treatment at a temperature of 0 ° C or higher and a holding time of 1 to 150 hours, cooling, and then the secondary heat treatment at a temperature of 300 to 450 ° C, the cubic orientation ratio is high. A method for obtaining an aluminum alloy foil for an electrolytic capacitor electrode is disclosed. Further, JP-A-4-231440 and JP-A-4-23
No. 2233 discloses that the intermediate annealing is performed in two steps, that is, after performing the primary intermediate annealing at a temperature of 450 ° C. or higher, it is cooled, and then kept at a temperature of 250 to 350 ° C. for 1 hour or more. Disclosed is a method for obtaining an aluminum alloy foil for electrolytic capacitor electrodes having a high cubic orientation ratio by performing secondary intermediate annealing for a certain period of time. Furthermore, JP-A-4-231442 discloses a method of performing hot rolling under specific conditions to obtain an aluminum alloy foil for electrolytic capacitor electrodes having a high cubic orientation ratio.

[0006]

On the basis of these prior arts, in order to form a large number of crystal grains having a cubic orientation in the obtained aluminum alloy foil or to grow the aluminum alloy foil rapidly, the production of the aluminum alloy foil is required. It depends on how the rolling or heat treatment is performed in the process. However, even if the above-mentioned prior art is adopted,
In some cases, an aluminum alloy foil having a sufficiently high cubic orientation ratio could not be obtained. Further, although the cubic orientation ratio is relatively high, an aluminum alloy foil with a relatively large amount of impurity precipitation is obtained. When this is used as an electrode foil for electrolytic capacitors by etching treatment, leakage current tends to occur due to the presence of impurities. There was also a drawback.

Therefore, as a result of further studies, the present inventor has conducted hot rolling in which heating is performed under heating, that is, hot rolling in which recovery / recrystallization of a metal structure and precipitation of impurities simultaneously proceed. I thought it would be an important factor. Then, by subjecting the aluminum plate to hot rolling under certain specific conditions, while preventing precipitation of impurities in the obtained aluminum alloy foil, a large number of crystal grains having a cubic orientation are formed and its growth is promoted. The inventors of the present invention have found out that they can do so and have reached the present invention. Therefore, the obtained aluminum alloy foil has excellent etching characteristics, so if this is etched into an electrode foil for electrolytic capacitors,
It is possible to obtain an electrode foil having a high capacitance and a small leakage current.

[0008]

Means for Solving the Problems That is, according to the present invention, basically, at the time of hot rolling, the pass rolling rate and the pass time in the falling temperature region I in which the temperature drops from 480 ° C. to 380 ° C., and / Or falling temperature range II where temperature falls from 380 ℃ to 280 ℃
The passing rolling ratio and the passing time in (1) are regulated within a certain range.

First, in the present invention, an aluminum ingot for hot rolling is prepared. As the aluminum ingot, one having a purity of 99.90% or more is used. Purity is 9
When an aluminum ingot of less than 9.90% is used, the amount of impurities is too large, and it becomes difficult to generate crystal grains having a cubic orientation, which makes it difficult to obtain an aluminum alloy foil having a high cubic orientation ratio, which is preferable. Absent. In addition, all% showing the ratio of each elemental component in an ingot or an aluminum alloy foil is weight%.

Before hot rolling, the aluminum ingot is subjected to a homogenizing treatment while being held at a temperature of 500 to 640 ° C. for a time of 1 to 50 hours. If the holding temperature in the homogenization treatment is less than 500 ° C, or if the holding time is less than 1 hour, the impurity elements in the aluminum ingot do not form a solid solution sufficiently uniformly, and the impurities in the obtained aluminum alloy foil are It is not preferable because much precipitation occurs. On the contrary, the holding temperature in homogenization treatment exceeds 640 ℃, or the holding time is
If the time exceeds 0 hours, the crystal grains generated in the aluminum ingot become coarse, and the crystal orientation becomes difficult to rotate to the cubic orientation even by the subsequent rolling or heat treatment, which is not preferable. If the holding temperature is too high, the energy efficiency is poor, and if the holding time is too long, the production efficiency is poor and the resulting aluminum alloy foil becomes expensive, which is not preferable.

The aluminum ingot subjected to the homogenizing treatment as described above is hot-rolled. In the hot rolling, the aluminum ingot is heated and rolled at the same time. Since the aluminum ingot is heated to a constant temperature by the homogenization treatment, it can be used as it is. However, since the temperature of the aluminum ingot is higher than the ambient temperature, the temperature of the aluminum ingot decreases before the hot rolling is introduced and during the hot rolling. The basic feature of the present invention is to regulate the rolling rate of the aluminum plate in the process of lowering the temperature of the aluminum ingot and the passage time of the aluminum plate in the process of lowering the temperature of the aluminum plate within a certain range. . Since the aluminum ingot becomes an aluminum plate when rolled, it is referred to as an aluminum plate in the present invention after being introduced into the hot rolling.

As one of the specific contents of this regulation, there is a hot rolling regulation example 1 shown below. That is, this Hot Rolling Regulation Example 1 shows that in the falling temperature region I in which the temperature of the aluminum plate falls from 480 ° C to 380 ° C during hot rolling,
The passing rolling rate is 50 to 95%, and the passing time of the aluminum plate in the falling temperature region I is 10 seconds to 15 minutes. Here, the pass rolling rate means the rolling rate in the falling temperature region. That is, if the thickness of the aluminum ingot before hot rolling introduced with t _0, the thickness of the aluminum plate in the lowered temperature region and t _a, passes through the rolling rate _{(%) = [(t 0} -t a) / t ₀ ] × 100. The thickness t _a of the aluminum plate in the lowered temperature range, while passing through the descending temperature zone gradually becomes thinner by rolling. Therefore, the pass rolling rate also gradually increases. But,
It means that both the minimum value and the maximum value of the pass rolling rate must be within the range of 50 to 95%.

If the pass rolling ratio in the falling temperature region I may take a value of less than 50%, the workability by rolling is small and the crystal grains having a cubic orientation (cubic oriented grains).
Is less preferable because it is less likely to form. On the other hand, if the pass rolling ratio exceeds 95% in some cases, the workability due to rolling is too large, and the recrystallization rate becomes too fast, and the strain energy for forming cubic oriented grains is sufficient. It is not preferable because it is not accumulated. Further, if the passage time of the aluminum plate in the falling temperature region I is less than 10 seconds, the formation of recrystallized grains is insufficient, which is not preferable. On the contrary, if the passage time exceeds 15 minutes, impurities are likely to precipitate, which is not preferable. The most preferable passage time is about 3 minutes.

In the case of hot rolling regulation example 1, after the hot rolling is finished, the aluminum plate is heated to a temperature of 280 to 380 ° C. for 1 hour.
Intermediate annealing may be performed for a period of minutes to 10 hours. The reason for this is that when such an intermediate annealing is performed, more cubic oriented grains are formed or the growth of already formed cubic oriented grains is promoted. If the temperature of the intermediate annealing is less than 280 ° C. or the time is less than 1 minute, there is a tendency that the formation of cubic oriented grains is not promoted. Further, if the temperature of the intermediate annealing exceeds 380 ° C. or the time exceeds 10 hours, the crystal grains are likely to become coarse and finally the cubic oriented grains tend to grow less easily. The intermediate annealing may be performed without cooling the aluminum plate after the hot rolling is finished, or may be performed after cooling.

In the case of Hot Rolling Regulation Example 1, cold rolling is performed after the hot rolling is completed or after the above-mentioned intermediate annealing is completed. The cold rolling rate is preferably 70 to 99.5%. This is to promote the formation and growth of cubic oriented grains and to reduce the thickness to form a foil. . Here, the cold rolling rate is, if the thickness of the aluminum sheet before introducing the cold rolling is t ₁ and the thickness of the aluminum sheet after introducing the cold rolling is t ₂ , the cold rolling rate (%) =
It is represented by [(t ₁ −t ₂ ) / t ₁ ] × 100.
If the cold rolling ratio is less than 70%, the strain energy for forming cubic oriented grains tends to be insufficiently accumulated. On the contrary, if the cold rolling ratio exceeds 99.5%, the texture other than the cubic orientation is excessively formed, so that the cubic orientation tends to be decreased even by the subsequent heat treatment.

After the cold rolling, the temperature is set to 150.
Intermediate annealing may be performed at ˜350 ° C. for 1 minute to 20 hours. This intermediate annealing also promotes the formation and growth of cubic oriented grains. If the temperature of this intermediate annealing is less than 150 ° C. or the time is less than 1 minute, the formation of cubic oriented grains tends to decrease. If the temperature of this intermediate annealing exceeds 350 ° C. or the time exceeds 20 hours, cubic oriented grains and crystal grains of other orientations become coarse, and the cubic orientation ratio tends to decrease.

After performing the above-mentioned intermediate annealing, 10
Finish rolling may be performed at a finish rolling rate of up to 30%. This finish rolling also promotes the formation and growth of cubic oriented grains. Here, the finish rolling rate is, assuming that the thickness of the aluminum sheet before introducing the finish rolling is t ₃ and the thickness of the aluminum sheet after introducing the finish rolling is t ₄ , the finish rolling rate (%) =
It is represented by [(t ₃ −t ₄ ) / t ₃ ] × 100.
If the finish rolling rate is less than 10%, it tends to be difficult to apply a sufficient driving force for growing cubic oriented grains. On the other hand, if the finish rolling rate exceeds 30%, the already formed cubic oriented grains tend to rotate and change to another orientation.

After cold rolling or finish rolling, final annealing is performed at a temperature of 450 to 580 ° C. Particularly preferably, the final annealing is performed at a temperature of 500 to 580 ° C. This final annealing promotes the growth of cubic oriented grains. Therefore, by performing this final annealing, an aluminum alloy foil for electrolytic capacitor electrodes having a high cubic orientation ratio can be obtained. When the temperature of this final annealing is less than 450 ° C., cubic oriented grains tend not to grow sufficiently. On the other hand, when the temperature of the final annealing exceeds 580 ° C, the oxide film on the surface of the obtained aluminum alloy foil becomes thick and it tends to be difficult to be etched.

In the case of Hot Rolling Regulation Example 1, when the aluminum plate is cooled after the hot rolling is finished and before the cold rolling is performed, or after the hot rolling is finished and before the intermediate annealing is performed. The cooling rate is preferably 1 ° C./minute or more. This cooling treatment is for preventing the precipitation of impurities in the aluminum plate. If the cooling rate is less than 1 ° C./minute, the amount of impurities deposited tends to increase.

Further, as another example of the specific content of the regulation of the hot rolling conditions, the following hot rolling regulation example 2 can be cited. That is, in this hot rolling regulation example 2, in the falling temperature region II in which the temperature of the aluminum sheet decreases from 380 ° C. to 280 ° C. during the hot rolling, the passing rolling rate is set to 75 to 99.9%, and this falling temperature region II The passage time of the aluminum plate in 10 is 15 seconds to 15 minutes. Here, the pass rolling rate has the same meaning as defined in Hot Rolling Regulation Example 1 described above.

If the pass rolling ratio in the falling temperature region II is less than 75% in some cases, the workability by rolling is small and the formation of cubic oriented grains is reduced, which is not preferable. On the other hand, if the pass rolling ratio may exceed 99.9%, the workability due to rolling is too large and the recrystallization rate becomes too fast, so that the strain energy for forming cubic oriented grains is sufficient. It is not preferable because it is not accumulated. Further, if the passage time of the aluminum plate in the falling temperature region II is less than 10 seconds, the formation of recrystallized grains is insufficient, which is not preferable. On the contrary, this transit time
If it exceeds 15 minutes, impurities tend to precipitate. The most preferable passage time is about 3 minutes.

Also in the case of Hot Rolling Regulation Example 2, it is preferable to cool the aluminum plate at a cooling rate of 1 ° C./minute or more after the hot rolling is completed. This cooling treatment is to prevent precipitation of impurities in the aluminum plate, as in the case of Hot Rolling Regulation Example 1. If the cooling rate is less than 1 ° C./minute, the amount of impurities deposited tends to increase.

After cooling the aluminum plate, if desired, cold rolling is performed. The cold rolling rate is preferably 70 to 99.5%. This is to promote the formation and growth of cubic oriented grains and to reduce the thickness to form a foil. . Here, the cold rolling rate has the same meaning as defined in Hot Rolling Regulation Example 1 described above. If the cold rolling ratio is less than 70%, the strain energy for forming cubic oriented grains tends to be insufficiently accumulated.
On the contrary, if the cold rolling ratio exceeds 99.5%, the texture other than the cubic orientation is excessively formed, so that the cubic orientation tends to be decreased even by the subsequent heat treatment.

After the cold rolling, the temperature is 150 to 350 ° C.
In addition, the intermediate annealing may be performed for 1 minute to 20 hours. This intermediate annealing also promotes the formation and growth of cubic oriented grains. If the temperature of this intermediate annealing is less than 150 ° C. or the time is less than 1 minute, the formation of cubic oriented grains tends to decrease. If the temperature of this intermediate annealing exceeds 350 ° C. or the time exceeds 20 hours, cubic oriented grains and crystal grains of other orientations become coarse, and the cubic orientation ratio tends to decrease.

After performing the above-mentioned intermediate annealing, 10
Finish rolling may be performed at a finish rolling rate of up to 30%. This finish rolling also promotes the formation and growth of cubic oriented grains. Here, the finish rolling rate has the same meaning as defined in Hot Rolling Regulation Example 1 described above. Finish rolling rate
If it is less than 10%, it tends to be difficult to apply a sufficient driving force for growing cubic oriented grains. On the other hand, if the finish rolling rate exceeds 30%, the already formed cubic oriented grains tend to rotate and change to another orientation.

After the hot rolling is finished, the aluminum plate is optionally cooled, cold-rolled or finish-rolled, and finally annealed at a temperature of 450 to 580 ° C. Particularly preferably, the final annealing is performed at a temperature of 500 to 580 ° C. This final annealing promotes the growth of cubic oriented grains. Therefore, by performing this final annealing, an aluminum alloy foil for electrolytic capacitor electrodes having a high cubic orientation ratio can be obtained. When the temperature of this final annealing is less than 450 ° C., cubic oriented grains tend not to grow sufficiently. On the other hand, when the temperature of the final annealing exceeds 580 ° C, the oxide film on the surface of the obtained aluminum alloy foil becomes thick and it tends to be difficult to be etched.

Further, as another example of the specific contents of the regulation of the hot rolling conditions, there is a hot rolling regulation example 3 shown below. That is, in this hot rolling regulation example 3, in the falling temperature region I in which the temperature of the aluminum sheet decreases from 480 ° C. to 380 ° C. during the hot rolling, the passing rolling rate is set to 50 to 95%, and this falling temperature region I The passage time of the aluminum plate in
Along with 1 to 15 minutes, in the falling temperature region II where the temperature of the aluminum plate falls from 380 ° C to 280 ° C, the passing rolling rate is set to 75 to 99.9%, and the passage time of the aluminum plate in this falling temperature region II is It should be 1 minute to 3 hours. Here, the pass rolling rate has the same meaning as previously defined.

The passing rolling ratio in the falling temperature region I is 50
If the value is less than%, the workability by rolling is small and the formation of cubic oriented grains is reduced, which is not preferable. On the other hand, if the pass rolling ratio exceeds 95% in some cases, the workability due to rolling is too large, and the recrystallization rate becomes too fast, and the strain energy for forming cubic oriented grains is sufficient. It is not preferable because it is not accumulated. Further, when the passage time of the aluminum plate in the falling temperature region I is less than 1 minute, the recrystallized grains tend to be insufficiently formed. On the contrary, if the passage time exceeds 15 minutes, impurities are likely to precipitate, which is not preferable. The most preferable passage time is about 3 minutes.

If the passing rolling ratio in the falling temperature region II subsequent to the falling temperature region I has a value of less than 75% in some cases, the workability by rolling is small and the formation of cubic oriented grains is reduced, which is preferable. Absent. Conversely, the passing rolling rate is 9
If the value exceeds 9.9%, the workability due to rolling is too large, and the recrystallization rate becomes too fast.
Strain energy for forming cubic oriented grains is not sufficiently accumulated, which is not preferable. Also, the falling temperature region II
If the passage time of the aluminum plate in 1 is less than 1 minute, the formation of recrystallized grains tends to be insufficient. On the contrary, if the passage time exceeds 3 hours, impurities are likely to precipitate, which is not preferable. The most preferable passage time is about 3 minutes.

The time required for the aluminum plate to be introduced into the falling temperature region II after passing through the falling temperature region I is 10
It is preferably from seconds to 5 minutes. If this time is less than 10 seconds, the temperature of the aluminum plate immediately drops after passing through the falling temperature region I, so that the holding time at a constant temperature becomes too short and the formation of cubic oriented grains tends to decrease. Occurs. On the contrary, if this time exceeds 5 minutes, the holding time at a constant temperature becomes too long, and there is a possibility that impurities may precipitate.

In the case of Hot Rolling Regulation Example 3, it is preferable to cool the aluminum plate at a cooling rate of 1.5 ° C./min or more after the hot rolling is completed. This cooling treatment is to prevent precipitation of impurities in the aluminum plate, as in the case of Hot Rolling Regulation Example 1. If the cooling rate is less than 1.5 ° C./minute, the amount of precipitated impurities tends to increase.

After cooling the aluminum plate, if desired, cold rolling is performed. The cold rolling rate is preferably 70 to 99%. This is to promote the formation and growth of cubic oriented grains and to reduce the thickness to form a foil. Here, the cold rolling rate has the same meaning as defined above. If the cold rolling ratio is less than 70%, the strain energy for forming cubic oriented grains tends to be insufficiently accumulated. On the contrary, this cold rolling rate
If it exceeds 99%, a texture other than the cubic orientation is excessively formed, so that the subsequent heat treatment tends to reduce the formation of the cubic orientation.

After the cold rolling, the temperature is 150 to 350 ° C.
In addition, the intermediate annealing may be performed for 1 minute to 20 hours. This intermediate annealing also promotes the formation and growth of cubic oriented grains. If the temperature of this intermediate annealing is less than 150 ° C. or the time is less than 1 minute, the formation of cubic oriented grains tends to decrease. If the temperature of this intermediate annealing exceeds 350 ° C. or the time exceeds 20 hours, cubic oriented grains and crystal grains of other orientations become coarse, and the cubic orientation ratio tends to decrease.

After performing the above-mentioned intermediate annealing, 10
Finish rolling may be performed at a finish rolling rate of up to 30%. This finish rolling also promotes the formation and growth of cubic oriented grains. Here, the finish rolling rate has the same meaning as defined above. If the finish rolling rate is less than 10%, it tends to be difficult to apply a sufficient driving force for growing cubic oriented grains. On the contrary, if the finish rolling rate exceeds 30%,
The already formed cubic oriented grains tend to rotate and change to another orientation.

After cold rolling or finish rolling, final annealing is performed at a temperature of 450 to 580 ° C. Particularly preferably, the final annealing is performed at a temperature of 500 to 580 ° C. This final annealing promotes the growth of cubic oriented grains. Therefore, by performing this final annealing, an aluminum alloy foil for electrolytic capacitor electrodes having a high cubic orientation ratio can be obtained. When the temperature of this final annealing is less than 450 ° C., cubic oriented grains tend not to grow sufficiently. On the other hand, when the temperature of the final annealing exceeds 580 ° C, the oxide film on the surface of the obtained aluminum alloy foil becomes thick and it tends to be difficult to be etched.

As described above, the conditions for hot rolling can be set as in Hot Rolling Regulation Example 1, 2 or 3 to obtain an aluminum alloy foil for electrolytic capacitor electrodes. Then, by etching the obtained aluminum alloy foil to form an electrode foil for an electrolytic capacitor, it is possible to obtain one having a high capacitance and a small leakage current.

[0037]

【Example】

Examples 1 to 9 and Comparative Examples 1 to 5 (Example of Hot Rolling Restriction Example 1) First, aluminum ingots having an elemental composition shown in Table 1 (thickness 40
0 mm) was prepared. After this aluminum ingot is homogenized under the conditions shown in Table 2, during hot rolling, the passing rolling rate and the passing rate in the falling temperature region I (the temperature region in which the temperature of the aluminum plate drops from 480 ° C to 380 ° C) The time was set as the conditions shown in Table 2. Then, the aluminum plate after completion of hot rolling was cooled and further cold rolled to obtain an aluminum alloy foil having a thickness of 0.1 mm. After degreasing and removing the adhered oil and the like on the foil surface with acetone, final annealing was performed under the conditions of temperature 530 ° C., time 10 hours and pressure 10 ⁻³ Pa to obtain an aluminum alloy foil for electrolytic capacitor electrodes.

[0038]

[Table 1]

[0039]

[Table 2]

Then, the cubic orientation ratio (%) and the electrostatic capacity (nF / cm ² ) of the obtained aluminum alloy foil for electrolytic capacitor electrodes were measured and shown in Table 2. The cubic orientation ratio (%) and capacitance (nF / cm ² ) are measured by
As described below. [Cube azimuth ratio] The aluminum alloy foil for electrolytic capacitor electrodes was immersed for 15 seconds in a solution with a volume ratio of hydrochloric acid: nitric acid: hydrofluoric acid = 50: 47: 3 and macro-etched to reveal the texture of the foil. Using an analyzer, the proportion of crystal grains having a cubic orientation (cubic oriented grains) in the visual field was determined by the area ratio. [Capacitance] The obtained aluminum alloy foil for electrolytic capacitor electrodes was subjected to [5.1% HCl + 6.4% AlCl ₃ 6H ₂ O + 6.
8% H ₂ SO ₄ ] solution, and etched at DC 0.16 A / cm ² for 8 minutes. Then, the etched foil is
It was immersed in a 5% H ₃ BO ₃ aqueous solution at 0 ° C. and subjected to chemical conversion treatment at 375 V. for 30 minutes. And the foil that has undergone chemical conversion treatment (size 1 cm x 2
cm) was immersed in 4.5% H ₃ BO ₃ aqueous solution, and the capacitance was measured using an LCR meter in a 120 Hz series equivalent circuit.

As is clear from these results, Examples 1 to 1
The aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to No. 9 had a relatively high cubic orientation ratio and electrostatic capacity. On the other hand, the method according to Comparative Example 1 is too short in the falling temperature region I, and the method according to Comparative Example 2 is too long in the falling temperature region I, so that the other conditions are the same. Compared with the aluminum alloy foils for electrolytic capacitor electrodes obtained by the methods according to Examples 5 and 6, the cubic orientation ratio was low and the electrostatic capacity was low. In the method according to Comparative Example 3, since the passing rolling rate in the falling temperature region I was too small, a cubic shape was obtained as compared with the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 9 under the same other conditions. The azimuth ratio was low and the electrostatic capacity was low. In the method according to Comparative Example 4, since the temperature of the homogenization treatment is too high,
Compared with the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 9 in which the other conditions were the same, the cubic orientation ratio was low and the capacitance was low.
In the method according to Comparative Example 5, the aluminum purity of the aluminum ingot to be used is too low, so that the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Examples 8 and 9 under the same other conditions is used. The cube orientation ratio was low and the electrostatic capacity was low.

Examples 10 to 19 and Comparative Example 6 (Example of Hot Rolling Regulation Example 1) The aluminum ingot used was changed as shown in Table 3, and after the hot rolling was finished, the cooling shown in Table 3 was performed. An aluminum alloy foil for electrolytic capacitor electrodes was obtained in the same manner as in Example 1 except that the step of performing intermediate annealing under the conditions shown in Table 3 was added immediately after cooling the aluminum plate at a speed. The cubic orientation ratio (%) and capacitance (nF / c) of the obtained aluminum alloy foil for electrolytic capacitor electrodes were measured.
m ² ) was measured and shown in Table 3.

[0043]

[Table 3]

As is clear from these results, the results of Examples 10 to
The aluminum foil for electrolytic capacitor electrodes obtained by the method according to No. 19 had a relatively high cubic orientation ratio and capacitance. On the other hand, in the case of using the ingot having too low aluminum purity, the cubic orientation ratio was low and the electrostatic capacity was low even if the other conditions were the same as in Example 19. The method according to Example 18 in which the temperature and time of the intermediate annealing are insufficient, and the aluminum foil for electrolytic capacitor electrodes obtained by the method according to Example 19 in which the temperature of the intermediate annealing is too high and the time is too long, Other conditions are the same, compared to those obtained by the method according to Examples 13 and 14,
The cubic orientation ratio was slightly low, and the capacitance was also slightly low.

Examples 20 to 37 and Comparative Example 7 (Example of Hot Rolling Restriction Example 1) First, aluminum ingots (thickness 400 mm) of the elemental composition related to alloy No. shown in Table 4 were prepared. This aluminum ingot was hot-rolled under the same conditions as in Example 1. Then, the aluminum plate after the hot rolling is cooled under the conditions shown in Table 4, and further cold-rolled so as to obtain the cold rolling rate shown in Table 4, and an aluminum foil having a thickness of 0.13 mm is obtained. Obtained. Thereafter, this aluminum foil was subjected to intermediate annealing under the conditions shown in Table 4, and further subjected to finish rolling so as to obtain the finish rolling rate shown in Table 4, to obtain an aluminum alloy foil having a thickness of 0.1 mm. After degreasing and removing the oil on the foil surface with acetone, the temperature is 530 ° C, the time is 10 hours, and the pressure is 10 ^-3 P.
Final annealing was performed under the condition of a to obtain an aluminum alloy foil for electrolytic capacitor electrodes. The cubic orientation ratio (%) of the obtained aluminum alloy foil for electrolytic capacitor electrodes
And capacitance (nF / cm ² ) were measured and are shown in Table 4.

[0046]

[Table 4]

As is clear from this result, Example 20-
The aluminum foil for electrolytic capacitor electrodes obtained by the method according to No. 37 had a relatively high cubic orientation ratio and capacitance. On the other hand, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 7 using the ingot with too low aluminum purity has a cubic orientation even if the other conditions are the same as in Example 24. The ratio was low and the electrostatic capacity was also low. Incidentally, in the cold rolling before intermediate annealing, the cold rolling rate is too low Example 34 and the cold rolling rate is too high aluminum electrolytic alloy electrode electrode foil obtained by the method according to Example 35, other Compared with the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 24 under the same conditions, the cubic orientation ratio was slightly lower and the electrostatic capacity was also slightly lower. Further, the method according to Example 32 in which the temperature and time of intermediate annealing after cold rolling are insufficient, and the electrolytic capacitor electrode obtained by the method according to Example 33 in which the temperature of the intermediate annealing is too high and the time is too long The aluminum foil for use also has the same other conditions, as compared with the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Examples 22 to 24, the cubic orientation ratio is slightly lower, and the capacitance is also slightly lower. It was a thing. Furthermore, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 36 in which the finish rolling rate is too low and the finish rolling rate is too high in Example 37, other conditions are the same, Example 24
The cubic orientation ratio was slightly lower than that of the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to (1), and the electrostatic capacity was also slightly lower.

Examples 38 to 53 and Comparative Example 8 (Example of Hot Rolling Restriction Example 1) First, aluminum ingots (thickness 400 mm) of the elemental composition related to alloy No. shown in Table 5 were prepared. This aluminum ingot was hot-rolled under the same conditions as in Example 1. After cooling the aluminum plate after the hot rolling under the conditions shown in Table 5, the primary intermediate annealing was performed under the conditions shown in Table 5 so that the cold rolling rate became 97.8%. Cold rolling was performed to obtain an aluminum foil having a thickness of 0.13 mm. Then, this aluminum foil was subjected to secondary intermediate annealing under the conditions shown in Table 5, and further finish-rolled so as to obtain the finish rolling rate shown in Table 5, to obtain an aluminum alloy foil having a thickness of 0.1 mm. It was After degreasing and removing the oil on the foil surface with acetone, the temperature is 530 ℃, the time is 10 hours, and the pressure is 10 ^-3 Pa.
Final annealing was performed under the conditions described above to obtain an aluminum alloy foil for electrolytic capacitor electrodes. Then, the cubic orientation ratio (%) and the capacitance (nF / cm ² ) of the obtained aluminum alloy foil for electrolytic capacitor electrodes were measured and shown in Table 5.

[0049]

[Table 5]

As is clear from the results in Table 5, Example 38
The aluminum foil for electrolytic capacitor electrodes obtained by the method according to ~ 53 had a relatively high cubic orientation ratio and capacitance. On the other hand, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 8 using the ingot with too low aluminum purity has a cubic orientation even if the other conditions are the same as in Example 38. The ratio is low,
Moreover, the electrostatic capacity was also low. The method according to Example 49 in which the temperature and time of the primary intermediate annealing are insufficient, and the electrolytic capacitor electrode aluminum obtained by the method according to Example 50 in which the temperature of the intermediate annealing is too high and the time is too long The alloy foil has a slightly lower cubic orientation ratio and a slightly smaller capacitance than the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 38, 41, or 42 under the same other conditions. It was low. Further, the method according to Example 51 in which the temperature and time of the intermediate annealing after cold rolling are insufficient, and the electrolytic capacitor electrode obtained by the method according to Example 52 in which the temperature of the intermediate annealing is too high and the time is too long Aluminum foil for use also has a slightly lower cubic orientation ratio and slightly lower capacitance than the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 43 or 44 under the same other conditions. Met. Further, the finishing rolling rate is too high, the electrolytic alloy electrode aluminum alloy foil obtained by the method according to Example 53, the other conditions are the same, the electrolytic capacitor electrode aluminum alloy obtained by the method according to Example 52 The cubic orientation ratio was slightly lower than that of the foil, and the capacitance was also slightly lower.

Examples 54 to 64 and Comparative Examples 9 to 15 (Examples of Hot Rolling Restriction Example 2) First, aluminum ingots (thickness 400 mm) of the elemental composition related to alloy No. shown in Table 6 were prepared. After homogenizing the aluminum ingot under the conditions shown in Table 6, during hot rolling,
Falling temperature range II (Aluminum plate temperature is 380 ℃ to 280 ℃)
The passing rolling ratio and the passing time in the temperature range of decreasing to 0 ° C.) are the conditions shown in Table 6. Then, after cooling the aluminum plate after the hot rolling under the conditions shown in Table 7, Table 7
Cold rolling is performed so that the cold rolling ratio shown in
An aluminum foil having a thickness of 0.1 mm was obtained. After degreasing and removing the adhering oil on the foil surface with acetone,
Final annealing was performed under conditions of ℃, time 10 hours and pressure 10 ^-3 Pa to obtain an aluminum alloy foil for electrolytic capacitor electrodes.
Then, the cubic orientation ratio (%) and the capacitance (nF / cm ² ) of the obtained aluminum alloy foil for electrolytic capacitor electrodes were measured, and shown in Table 7.

[0052]

[Table 6]

[0053]

[Table 7]

As is clear from the results in Table 7, Example 54
The aluminum foils for electrolytic capacitor electrodes obtained by the methods according to ~ 63 had relatively high cubic orientation ratio and capacitance. On the other hand, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Examples 9 and 14 in which the homogenization treatment temperature is too high and the method according to Comparative Example 10 in which the homogenization treatment temperature is too low has a cubic orientation ratio. Is low,
The electrostatic capacity was also low. Also, the falling temperature range
The method according to Comparative Example 11 where the passing time of II is too short, and the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 12 where the passing time of the falling temperature region II is too long,
Compared with the method according to Example 57 in which the other conditions were the same, the cubic orientation ratio was low and the electrostatic capacity was also low. Comparative example in which the rolling reduction rate is too low in the falling temperature range
The aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to 13 had a lower cubic orientation ratio and a lower capacitance than the method according to Example 57 in which other conditions were the same. . The aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 15 using an ingot having too low an aluminum purity had an extremely low cubic orientation ratio and an extremely low electrostatic capacity.

Examples 61 to 63 in which the cooling rate after hot rolling was slowed or the cold rolling rate was lowered or increased
The electrolytic capacitor electrode aluminum alloy foil obtained by the method according to, compared with the electrolytic capacitor electrode aluminum alloy foil obtained by the method according to Example 57, the other conditions being the same, the cubic orientation ratio is slightly reduced. In addition, the electrostatic capacity was slightly reduced.

Examples 65 to 83 and Comparative Example 16 (Regulation of hot rolling)
Example 2) First, aluminum of the elemental composition related to alloy No. shown in Table 8
An ingot (thickness 400 mm) was prepared. This aluminum ingot
Was hot-rolled under the same conditions as in Example 54. That
Table 8 shows the aluminum plate after the hot rolling is finished.
After cooling according to the conditions, the cold rolling rate becomes the value shown in Table 8.
Cold-rolled to give a 0.13 mm thick aluminum foil.
Obtained. Then, the conditions shown in Table 8 for this aluminum foil
Intermediate annealing is applied to obtain the finish rolling rate shown in Table 8.
Finish rolling, and then 0.1 mm thick aluminum alloy
I got gold leaf. The oil on the foil surface is removed by acetone.
After degreasing and removing, temperature 530 ℃, time 10 hours and pressure 10
^-3For electrolytic capacitor electrode after final annealing under Pa condition
An aluminum alloy foil was obtained. And the obtained electrolytic con
Cubic orientation ratio of aluminum alloy foil for dense electrode
(%) And capacitance (nF / cm ²) And measured and shown in Table 8
It was

[0057]

[Table 8]

As is clear from the results in Table 8, Example 65
The aluminum foil for electrolytic capacitor electrodes obtained by the method according to ~ 83 had a relatively high cubic orientation ratio and capacitance. On the other hand, using an ingot whose aluminum purity is too low, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 16 has a cubic orientation even if other conditions are the same as those of Example 65. The ratio is low,
Moreover, the electrostatic capacity was also low. Incidentally, the cooling rate after hot rolling is slow, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 76, other conditions are the same as those obtained by the method according to Example 65. Compared to,
The cubic orientation ratio was slightly reduced, and the electrostatic capacity was also slightly low. Further, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Examples 77 and 83 in which the temperature of the intermediate annealing is low and the time is short, or the method according to Example 78 in which the temperature of the intermediate annealing is high and the time is long is The cubic orientation ratio was slightly lower than that obtained by the method according to Example 65 under the same other conditions, and the capacitance was also slightly lower. In the cold rolling before intermediate annealing, the method according to Example 79 having a low cold rolling rate, or the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 80 having a too high cold rolling rate, Compared with the one obtained by the method according to Example 65 under the same conditions, the cubic orientation ratio was slightly reduced, and the electrostatic capacity was also slightly low. In addition, an example in which the finish rolling rate is too low
The method according to 81, or the finishing rolling rate is too high aluminum electrolytic foil for electrolytic capacitor electrodes obtained by the method according to Example 82, other conditions are the same as those obtained by the method according to Example 65 In comparison, the cubic orientation ratio was slightly reduced, and the capacitance was also slightly low.

Examples 84 to 98 and Comparative Examples 17 to 21 (Example of Hot Rolling Restriction Example 3) First, aluminum ingots (thickness 400 mm) of the elemental composition related to alloy No. shown in Table 9 were prepared. After homogenizing the aluminum ingot under the conditions shown in Table 9, during hot rolling,
Falling temperature range I (Aluminum plate temperature is 480 ℃ to 380 ℃)
The passing rolling ratio and the passing time in the temperature range (decreasing to ℃) were set as the conditions shown in Table 9. Then, the passing rolling rate and the passing time in the falling temperature region II (the temperature region in which the temperature of the aluminum plate drops from 380 ° C. to 280 ° C.) following the falling temperature region I were set as the conditions shown in Table 10. The time (I → II time) after passing through the falling temperature region I and before being introduced into the falling temperature region II was set as the condition shown in Table 10. Cooling the aluminum plate after finishing hot rolling in this way,
Further cold rolling was performed to obtain an aluminum alloy foil having a thickness of 0.1 mm. After degreasing and removing the oil on the foil surface with acetone, the temperature is 530 ° C, the time is 10 hours, and the pressure is 10 ^-3 P.
Final annealing was performed under the condition of a to obtain an aluminum alloy foil for electrolytic capacitor electrodes. The cubic orientation ratio (%) of the obtained aluminum alloy foil for electrolytic capacitor electrodes
And capacitance (nF / cm ² ) were measured and are shown in Table 10.

[0060]

[Table 9]

[0061]

[Table 10]

As is clear from the results in Table 10, Example 84
The aluminum foil for electrolytic capacitor electrodes obtained by the method according to ~ 98 has a relatively high cubic orientation ratio and capacitance. On the other hand, the method according to Comparative Examples 17 and 20 where the homogenization treatment temperature is too high, and the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 18 where the homogenization treatment temperature is too low is a cubic orientation ratio. Is low,
The electrostatic capacity was also low. The aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 19 having a low pass rolling rate in the falling temperature regions I and II was obtained by the method according to Example 95 under the same other conditions. Compared with the ones, the cubic orientation ratio was low and the capacitance was low. The aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Comparative Example 21 using an ingot having too low an aluminum purity had an extremely low cubic orientation ratio and an extremely low capacitance.

Examples 99 to 114 and Comparative Example 22 (Example of Hot Rolling Regulation Example 3) First, the aluminum ingots (thicknesses) according to alloy No.
400 mm) was prepared. In this aluminum ingot, Example 8
Hot rolling was performed under the same conditions as in 4. Then, after cooling the aluminum plate after the hot rolling under the conditions shown in Table 11, so as to have the cold rolling rate shown in Table 11, subjected to cold rolling, 0.13 mm thick aluminum foil Got afterwards,
This aluminum foil was subjected to intermediate annealing under the conditions shown in Table 11, and further subjected to finish rolling so as to obtain the finish rolling rate shown in Table 11, to obtain an aluminum alloy foil having a thickness of 0.1 mm. After degreasing and removing the adhered oil and the like on the foil surface with acetone, final annealing was performed under the conditions of temperature 530 ° C., time 10 hours and pressure 10 ⁻³ Pa to obtain an aluminum alloy foil for electrolytic capacitor electrodes. Then, the cubic orientation ratio (%) and the capacitance (nF / cm ² ) of the obtained aluminum alloy foil for electrolytic capacitor electrode were measured, and shown in Table 11.

[0064]

[Table 11]

As is clear from the results in Table 11, Example 99
The aluminum foils for electrolytic capacitor electrodes obtained by the methods according to ~ 114 had a relatively high cubic orientation ratio and electrostatic capacity. On the other hand, the method according to Comparative Example 22 using an ingot having a low aluminum purity is extremely low in cubic orientation ratio as compared with the method according to Example 99 in which other conditions are the same, and the capacitance is also Was extremely low. An example in which the cooling rate after the hot rolling was slightly lower
Aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to 109, the cubic orientation ratio is slightly lower than that obtained by the method according to Example 99 under the same other conditions, Was a little low. Further, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 110 having a low cold rolling rate before intermediate annealing is the same as that obtained by the method according to Example 99 in which other conditions are the same. In comparison, the cubic orientation ratio was slightly lower and the electrostatic capacity was slightly lower. Aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 111 in which the temperature of intermediate annealing is low and the time is short, or the method in accordance with Example 112 in which the temperature of the intermediate annealing is high and the time is long is other conditions. Of the same, the cube orientation ratio was slightly lower and the capacitance was slightly lower than that obtained by the method according to Example 99. Further, the method according to Example 113 having a low finish rolling rate, or the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to Example 114 having a high finish rolling rate, in Example 99 in which other conditions are the same. The cubic orientation ratio was slightly lower and the capacitance was slightly lower than that obtained by such a method.

[0066]

INDUSTRIAL APPLICABILITY As described above, the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to the present invention is subjected to hot rolling at the time of hot rolling regulation example 1, 2 or 3 described above.
Since the hot-rolling was performed, the cubic orientation ratio becomes high, and when the obtained aluminum alloy foil is subjected to etching treatment to be an electrode foil, an effect of obtaining an electrode foil having a high capacitance can be obtained. In addition, in the aluminum alloy foil for electrolytic capacitor electrodes obtained by the method according to the present invention, the precipitation of impurities is small, and when the electrode foil is used, the leakage current is also reduced. In particular, the method according to the present invention can obtain an aluminum alloy foil for electrolytic capacitor electrodes having a relatively high cubic orientation ratio even when applied to an aluminum ingot having an aluminum purity of about 99.96%. Therefore,
Even without using a high-purity aluminum ingot with an aluminum purity of more than 99.99%, it is possible to obtain a high-capacity electrode foil and use an inexpensive aluminum ingot with a relatively low purity. Also, it is possible to obtain an electrode foil having a high capacitance at low cost.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C22F 1/00 622 C22F 1/00 682 661 691B 682 691C 691 694A 694B 694 H01G 9/04 346 9/24 B (58) Field (Int.Cl. ⁷ , DB name) C22F 1/04-1/057 B21B 3/00 H01G 9/00-9/055

Claims (13)

(57) [Claims] 1. An aluminum ingot having a purity of 99.9% or more is homogenized by holding at a temperature of 500 to 640 ° C. for a time of 1 to 50 hours, and then subjected to the following conditions (1) and (2): Hot rolling, followed by cold rolling, then temperature 45
A method for producing an aluminum alloy foil for an electrolytic capacitor electrode, which comprises performing final annealing at 0 to 580 ° C. Note (1) in the falling temperature region I where the temperature falls from 480 ° C. to 380 ° C., the rolling reduction rate is 50 to 95%, (2) the passing time of the aluminum plate in the falling temperature region I is 10 seconds. ~ 15 minutes. 2. The method for producing an aluminum alloy foil for an electrolytic capacitor electrode according to claim 1, which further comprises a step of cooling the aluminum plate after the hot rolling and before the cold rolling at a cooling rate of 1 ° C./min or more. 3. The electrolysis according to claim 1, further comprising a step of subjecting the aluminum sheet after the hot rolling and before the cold rolling to an intermediate annealing at a temperature of 280 to 380 ° C. for a time of 1 minute to 10 hours. Manufacturing method of aluminum alloy foil for capacitor electrode. 4. The method for producing an aluminum alloy foil for an electrolytic capacitor electrode according to claim 1, wherein cold rolling is performed at a cold rolling rate of 70 to 99.5%. 5. A step of subjecting the aluminum plate after the cold rolling to an intermediate annealing again at a temperature of 150 to 350 ° C. for a time of 1 minute to 20 hours, and then to a finish rolling at a finish rolling rate of 10 to 30%. The method for producing an aluminum alloy foil for an electrolytic capacitor electrode according to any one of claims 1 to 4, further comprising: 6. An aluminum ingot having a purity of 99.9% or more is homogenized by holding at a temperature of 500 to 640 ° C. for a time of 1 to 50 hours, and then subjected to the following conditions (1) and (2): Hot rolling, followed by cold rolling, then temperature 45
A method for producing an aluminum alloy foil for an electrolytic capacitor electrode, which comprises performing final annealing at 0 to 580 ° C. Note (1) in the falling temperature region II where the temperature falls from 380 ° C. to 280 ° C., the rolling reduction is 75 to 99.9%, (2) the passing time of the aluminum plate in the falling temperature region II is 10 seconds. ~ 15 minutes. 7. The method for producing an aluminum alloy foil for an electrolytic capacitor electrode according to claim 6, which further comprises a step of cooling the aluminum plate after the hot rolling and before the cold rolling at a cooling rate of 1 ° C./min or more. 8. The method for producing an aluminum alloy foil for electrolytic capacitor electrodes according to claim 6, wherein cold rolling is performed at a cold rolling rate of 70 to 99.5%. 9. A step of subjecting an aluminum plate after completion of cold rolling to an intermediate annealing at a temperature of 150 to 350 ° C. for a time of 1 minute to 20 hours, and subsequently performing a finish rolling at a finish rolling rate of 10 to 30%. The method for producing an aluminum alloy foil for an electrolytic capacitor electrode according to any one of claims 6 to 8, which is added. 10. An aluminum ingot having a purity of 99.9% or more is subjected to a homogenization treatment by holding at a temperature of 500 to 640 ° C. for a time of 1 to 50 hours, and then subjected to the following conditions (1) to (4): Hot rolling, followed by cold rolling, then temperature 450
A method for producing an aluminum alloy foil for an electrolytic capacitor electrode, which comprises performing final annealing at 580 ° C. Note (1) in the falling temperature region I where the temperature falls from 480 ° C. to 380 ° C., the passing rolling rate is 50 to 95%, (2) the passing time of the aluminum plate in the falling temperature region I is 1 to 15 minutes, (3) in the falling temperature region II where the temperature drops from 380 ° C to 280 ° C, the passing rolling rate is 75 to 99.9%, (4) the passage of the aluminum plate in the falling temperature region II The time should be 1 minute to 3 hours. 11. The time required for the aluminum plate to be introduced into the descending temperature region II after passing through the descending temperature region I is 10.
11. The method for producing an aluminum alloy foil for an electrolytic capacitor electrode according to claim 10, which is for 2 seconds to 5 minutes. 12. The production of an aluminum alloy foil for an electrolytic capacitor electrode according to claim 10 or 11, which further comprises a step of cooling the aluminum plate after the hot rolling and before the cold rolling at a cooling rate of 1.5 ° C./min or more. Method. 13. After cooling the aluminum plate after completion of hot rolling, after performing cold rolling at a cold rolling rate of 70 to 99%,
An intermediate annealing is performed at a temperature of 150 to 350 ° C. and a time of 1 minute to 20 hours, and then a step of performing finish rolling at a finish rolling rate of 10 to 30% is added, and the method according to claim 10 or 12. Manufacturing method of aluminum alloy foil for electrolytic capacitor electrode.